AlpHaset Process and Molding Sands in Russia

The advantages of the AlpHaset process, the features of its application, the requirements for the materials used are considered. Molding sands, making in Russia are analyzed. It is noted that the consumption of molding and core mixture used in the manufacture of castings using this process is reduced by 3-4 times. The mixture after knocking out is regenerated up to 90%, which, in comparison with liquid glass, does not require the removal of spent molding and core mixtures to the dump, thereby, improving the environmental situation in the industrial zone. In addition, this process contributes to the introduction of environmentally friendly technological process of manufacturing castings in foundries of machine-building enterprises and individual foundries. The best values of strength are achieved on quartz sand, with a content of fine dust particles ranging in size from 0 to 0.125 mm less than 2% and a residue on the grid of 0.125 mm maximum 5%. The average grain size of such sand should be 0.25 - 0.30 mm. The molding sands produced in Russia are analyzed. The conclusion is made on the application of the AlpHaset process, based on the use of molding sand, produced according to Russian State Standard 2138-91.

The stability of the internal cavities of steel casting

The mechanism and causes of the formation of casting defects, manifested in the deviation of the geometry of the internal cavities from the «cylindrical», are investigated. It is shown that the causes of distortion of the geometric shape are associated with deformation of the casting rod during thermal and mechanical interaction with the melt. Using the possibilities of computer simulation in the MAGMASOFT package, the temperature distributions of the metal in the casting body during the casting and solidification were analyzed. Areas of distortion of the geometric shape of the inner part of the casting correspond to the area of the rod subjected to the highest and longest thermal loads. The characteristics of the temperature fields in the respective zones indicate overheating of individual areas of the rod to temperatures causing phase stresses in the structure of the core mixture, sufficient for the occurrence of deformations in it. To eliminate the defect under consideration, two approaches were used to reduce the magnitude of phase stresses in the casting rod and to adjust the design of the rod tooling.

PREPARATION OF DESULFURIZING ACTIVATED CARBON FROM CORN STALK AND CHARACTERIZATION OF DESULFURIZING STRUCTURE

This study investigated the optimal conditions for preparing desulfurizing stalk carbon, using corn stalk as a raw material and zinc chloride as an activator. The structure of stalk carbon was characterized using thermogravimetry (TG), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Brunauer – Emmelt – Teller (BET). Results found no significant difference in stalk carbon desulfurization properties when using stalk skin, core, or a skin-core mixture as raw material. The desulfurization performance of stalk carbon prepared using a skin-core mixture, was the most effective when the material : liquid ratio was 1:2; activation temperature was 350 °C; and activation time was 70 min. The corresponding H2S adsorption time was 74 min. The large specific surface area of 562.28 m2/g and abundant pore-volume of 0.3851 ml/g was found in the desulfurization stalk carbon prepared using these conditions. The increase in micropores and the abundant oxygen-containing functional surface groups were conducive to H2S adsorption. The desulfurization products were found to be mainly elemental S and sulfite.

THE ROLE OF REFRACTORY FILLER IN THE PROCESSES OF STRUCTURAL FORMATION OF CORE MIXTURES

The results of research, computer simulation of the influence of the shape of the grain of sand on the formation of the strength of the core mixture are presented. An essential dependence of the strength of the core on the quality characteristics of the refractory filler is established.

Evaluation of Some Pesticide Residues in Fruits import by High Performance Liquid Chromatography

Pesticide residues have been found in various fruits and vegetables. This study collected 24 samples and reported a method based on High Performance Liquid Chromatography (HPLC). For determination of pesticide residues used in Some fruits which were collected from different markets of Baghdad city to make) 24) samples from (peel , core, mixture) for each type of fruits markets as: Oranges( Egypt , Africa), Pomegranate ( Egypt), Mango ( Kenya ), Pears (China), Plum fruits ( Africa ) , Kiwi (Turkey ) .That detective of ( 5 ) different pesticides (diazinon, malathion, chlorpyrifos ,parathion and cypermethrin). The results were detected of multi-residues of pesticides on the fruit in ( peel , core , mixture ) may be in the limit of Maximum residue limits(MRL) or higher of it . The pesticides detected that exceeding the limits are: cypermethrin in Kiwi (peel, core and mixture)at(0.204,0.038, 0.537), in pomegranate detected in (peel and mixture) at (0.509,0.189) mg/kg , Diazinon detccted in Egyptian orange in (peel ,core and mixture) at (0.031,0.207, 0.099) mg/kg . Malathion and Parathion was not detected at any type of fruits and that results was compared with codex of FAO/WHO(2013). That data is important to monitor residues in food and to fill gaps in current knowledge would be helpful in assessing human exposure risks from ingestion of contaminated Fruits Imported to our country.

Evaluation of Some Pesticide Residues in Fruits import by High Performance Liquid Chromatography

Pesticide residues have been found in various fruits and vegetables. This studycollected 24 samples and reported a method based on High Performance Liquid Chromatography (HPLC). For determination of pesticide residues used in Some fruits which were collected from different markets of Baghdad city to make) 24) samples from (peel , core, mixture) for each type of fruits markets as: Oranges( Egypt , Africa), Pomegranate ( Egypt), Mango ( Kenya ), Pears (China), Plum fruits ( Africa ) , Kiwi (Turkey ) .That detective of ( 5 ) different pesticides (diazinon, malathion, chlorpyrifos ,parathion and cypermethrin). The results were detected of multi-residues of pesticides on the fruit in ( peel , core , mixture ) may be in the limit of Maximum residue limits(MRL) or higher of it . The pesticides detected that exceeding the limits are: cypermethrin in Kiwi (peel, core and mixture)at(0.204,0.038, 0.537), in pomegranate detected in (peel and mixture) at (0.509,0.189) mg/kg , Diazinondetccted in Egyptian orange in (peel ,core and mixture) at (0.031,0.207, 0.099) mg/kg . Malathion and Parathion was not detected at any type of fruits and that results was compared with codex of FAO/WHO(2013). That data is important to monitor residues in food and to fill gaps in current knowledge would be helpful in assessing human exposure risks from ingestion of contaminated Fruits Imported to our country .

A New Approach to Manufacturing Biocomposite Sandwich Structures: Mycelium-Based Cores

A new approach to manufacturing biocomposite sandwich structures is introduced. Materials used in the biocomposite are natural textile reinforcement, mycelium-bound agricultural waste as core, and bioresin. This paper focuses on three specific steps of the seven-step manufacturing process: filling pre-stamped textile shells with core mixture; allowing the core material to grow thereby binding reinforcement particles and textile skins into a unitized preform; and oven drying said preform to drive off moisture and inactivate the mycelium. Specific process details highlighted include design and thermoforming of growth trays, tray sterilization, filling trays with mycelium-inoculated substrates filling and allowing growth to occur, and finally conduction and convection drying/inactivation of the grown parts. To study the new material’s stiffness using different materials and under different processing conditions, specimen dimensions were based on ASTM D7250 and C393 standards. All dried samples were tested in flexure by three-point bending method to determine the stiffness and strength of the resin-less preforms and to identify optimal material combinations.

ASSESSMENT OF THE TRIBOLOGICAL PROPERTIES OF HARDFACING WELDING ALLOY Fe-Mn-C-B-Si-Ni-Cr IN DRY FRICTION CONDITIONS

The paper assesses the tribological properties of hardfacing coatings produced by gas metal arc welding. Flux-cored wires were used as a welding material. The core mixture was based on the Fe-Mn-C-B-Si-Ni-Cr alloy. Seven types of flux-cored wires with different compositions were prepared. The flux-cored wires had a diameter of 2.4 mm. The tribological assessment was performed with an Amsler tribotester under dry friction conditions at different unit pressures: 3, 7, and 10 MPa. The results demonstrate that the coating L-6 has good tribological properties. The overlay weld had a hardness of 49 HRC. Following friction testing, the coatings were also examined with respect to their microhardness and microstructure.